git/list[1] front-page[2] threads[3] people[4] search[5] about
 

Re: [PATCH] valgrind: ignore SSE-based strlen invalid reads

From
Carlos Martín Nieto <cmn@elego.de>
Date
Mar 16, 2011, 10:41 UTC
Message-ID
<1300272098.7214.5.camel@bee.lab.cmartin.tk>
In-Reply-To
<20110316095632.GA8277@elie>
On mié, 2011-03-16 at 04:56 -0500, Jonathan Nieder wrote:
Show 12 quoted lines
> Hi Carlos,
> 
> Carlos Martín Nieto wrote:
> 
> > The C library uses SSE instructions to make strlen (among others)
> > faster, loading 4 bytes at a time and reading past the end of the
> > allocated memory. This read is safe and when the strlen function is
> > inlined, it is (obviously) not replaced by valgrind, which reports a
> > false-possitive.
> 
> It would be GCC rather than the C library if the strlen is inlined, I
> think.  Is this a distinct bug from
 The strlen definition comes from the C library, as far as I know, but
I'll amend to say it's the GNU C Library that's doing weird things.
> <http://bugs.kde.org/show_bug.cgi?id=266961>?  Has it been filed
> with the valgrind maintainers?
 It looks like the same issue, which should also be
https://bugzilla.redhat.com/show_bug.cgi?id=518247 and
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=590640 which have
patches available. Newer versions of valgrind do not have this "bug".
   cmn
Previous: Jonathan NiederNext: Carlos Martín Nieto
Message 3 of 11 in “valgrind: ignore SSE-based strlen invalid reads”
  1. valgrind: ignore SSE-based strlen invalid readsCarlos Martín Nieto, Mar 16, 2011
  2. Jonathan NiederMar 16, 2011
  3. Carlos Martín NietoMar 16, 2011
  4. valgrind: ignore SSE-based strlen invalid readsCarlos Martín Nieto, Mar 16, 2011
  5. Jonathan NiederMar 16, 2011
  6. Carlos Martín NietoMar 16, 2011
  7. Jonathan NiederMar 16, 2011
  8. valgrind: ignore SSE-based strlen invalid readsCarlos Martín Nieto, Mar 16, 2011
  9. Junio C HamanoMar 16, 2011
  10. Carlos Martín NietoMar 16, 2011
  11. Andreas SchwabMar 16, 2011

Read the whole thread, see it on lore, or plain text.

$ cat FOOTERMessages come from the public archive at lore.kernel.org/git, fetched every hour. The front page is chosen and written each morning by an AI editor and can be wrong; the threads themselves are the record. About and API. For agents: an MCP server at https://gitlist.dev/mcp, and any thread, story or person page as Markdown by adding .md to its URL (or sending Accept: text/markdown). Details in /llms.txt.